The South Pole Telescope (SPT) is a 10 meter (394 in) diameter telescope located at the Amundsen-Scott South Pole Station, Antarctica. It is a microwave/millimeter-wave telescope that observes in a frequency range between 70 and 300 GHz.

SPT WebsiteThe South Pole Telescope (SPT) is a 10-meter telescope at the Amundsen-Scott South Pole research station. Taking advantage of the exceptionally clear, dry, and stable atmosphere at the South Pole, the SPT will map large areas of the sky with high sensitivity at millimeter and sub-millimeter wavelengths.

The initial goal of the SPT was to explore the nature of dark energy, an unexplained phenomenon responsible for the observed acceleration in the expansion of the universe. The SPT will search for massive clusters of galaxies by looking for spectral distortions in the cosmic microwave background. Dark energy inhibits the growth of galaxy clusters, so studying the population of clusters through cosmic time will constrain models of dark energy.

With the installation of the polarization sensitive SPTpol detector, SPT began a program of searching for B-mode polarization in the CMB. During the 2016-17 austral summer, SPT's focal plane has once again been updated with the SPT-3G instrument which will significantly increase its sensitivity as it searches for B-modes in the microwave sky.

This research is a collaboration among nine U.S. and Canadian institutions.